import {z} from 'zod'

export type GetApiV1TrainsOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const ag = z.object({destinationRailNetworkLocationName: z.string().optional(), emptyCarCount: z.number().int().optional(), estimatedShipmentAvailabilityDateTime: z.string().optional(), lastEventDateTime: z.string().optional(), lastEventDescription: z.string().optional(), lastEventRailNetworkLocationName: z.string().optional(), latitude: z.number().optional(), loadedCarCount: z.number().int().optional(), longitude: z.number().optional(), nextTrainId: z.string().optional(), originRailNetworkLocationName: z.string().optional(), shuttleTrainPermitNumber: z.string().optional(), shuttleOperatorCompanyAbbreviation: z.string().optional(), shuttleOrderRequesterAbbreviation: z.string().optional(), shuttleOwnerCompanyAbbreviation: z.string().optional(), trainId: z.string().optional()});

export const getApiV1TrainsResponse = z.object({elements: z.array(ag).optional()});

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Trains - Provides current status, with tracing details for all unit train types.
 * 
 * GET /v1/trains
 */
export const getApiV1Trains = async (options?: GetApiV1TrainsOptions) => {
const {baseUrl = "https://api.bnsf.com:6443", fetch: fetchFn = fetch} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('accept', "application/json")

const url = `${baseUrl.replace(/\/+$/, '')}/v1/trains${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "GET", headers})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(getApiV1TrainsResponse, await res.json())
};